Measures to mitigate the emissions of carbon dioxide (CO₂) can vary substantially in terms of the energy required. Some proposed CO₂ mitigation options involve energy-intensive processes that compromise their viability as routes to mitigation, especially if deployed at a global scale. Here we provide an assessment of different mitigation options in terms of their energy usage. We assess the relative effectiveness of several CO₂ mitigation routes by calculating the energy cost of carbon abatement (kilowatt-hour spent per kilogram CO₂-equivalent, or kWh kgCO₂e^–1) mitigated. We consider energy efficiency measures, decarbonizing electricity, heat, chemicals and fuels, and also capturing CO₂ from air. Among the routes considered, switching to renewable energy technologies (0.05–0.53 kWh kgCO₂e^–1 mitigated) offer more energy-effective mitigation than carbon embedding or carbon removal approaches, which are more energy intensive (0.99–10.03 kWh kgCO₂e^–1 and 0.78–2.93 kWh kgCO₂e^–1 mitigated, respectively), whereas energy efficiency measures, such as improving building lighting, can offer the most energy-effective mitigation.

减少二氧化碳（CO ₂）排放的措施在所需能量方面可能有很大不同。某些拟议的CO ₂减排方案涉及能源密集型过程，这些过程会削弱其作为减排途径的生存能力，尤其是在全球范围内部署时。在这里，我们根据能源使用情况评估了不同的缓解方案。我们通过计算碳减排的能源成本（每千克CO ₂当量或千瓦时kgCO ₂ e ^–1所花费的千瓦小时，来评估几种减少CO ₂途径的相对有效性。）缓解。我们考虑采取节能措施，对电，热，化学物质和燃料进行除碳，并从空气中捕获CO ₂。在考虑的路线中，转用可再生能源技术（减少0.05–0.53 kWh kgCO ₂ e ^–1）比碳包埋或除碳方法更加节能，而碳包埋或碳清除方法耗能更大（0.99–10.03 kWh kgCO ₂ e ^{–1）。 1}和0.78–2.93 kWh kgCO ₂ e ^–1分别降低），而能源效率措施（如改善建筑照明）可以提供最节能的缓解措施。